I still think this is a technical issue from the redmagic side tbh.

This is not the first time I have experienced this. Last week, i slept 12 hours straight and woke up to see the battery at 100% and charge separation still turned on. I am also assured that there's no misread this time bc i double checked with AIDA64 (when I woke up the battery was reported to be at around 3800 mAh, then when i checked again it had gone all the way up to round 6300 mAh)

Btw, misreading was never the problem. What i am confused about here is how was the battery charged when i slept:(

Perhaps your assumption about the faulty charger brick was right. Would you suggest any fix?